With the present invention in embodiments thereof, there is provided a photoconductive imaging member containing a photogenerating layer of mixed perylenes, such as those of U.S. Pat. No. 6,051,351, the disclosure of which is totally incorporated herein by reference, and which perylenes contain electron acceptors, or an electron acceptor, and which acceptor can enhance or increase the photosensitivity of the photogenerating layer by, for example, in embodiments about 40 percent, and more specifically, from about 15 to about 35 percent in embodiments.
The present invention is directed, more specifically, to photoconductive imaging members with a photogenerating perylene mixture containing three perylene dimers represented, for example, by Formulae A, B and C (535+), and an electron acceptor component. In embodiments, the weight of electron acceptor relative to the total weight of perylene dimers is, for example, about 0.1 to about 20 weight percent; and more specifically, for example, the amount of electron acceptor varies from about 0.9 percent to about 16.7 percent, and the mixed perylene dimer amount varies from about 99.1 to about 83.3 percent. For the mixed perylene dimer portion, excluding the electron acceptor, each perylene may be selected in an amount of from about 5 to about 90, and in embodiments from about 25 to about 50 weight percent. More specifically, the mixed perylene dimer can be comprised of about 25 percent of 1,3-bis(n-pentylimidoperyleneimido)propane, about 25 percent of 1,3-bis(2-methylbutylimidoperyleneimido)propane, and about 50 percent of 1-(n-pentylimido peryleneimido)-3-(2-methylbutylimido peryleneimido)propane. In the perylene mixture in embodiments, each perylene of Formulae A, B, and C can be present in an amount of from about 4 to about 80 or 90 weight percent, and the electron acceptor can be present in an amount of from about 0.1 to about 20 weight percent, and wherein the total of the perylene mixture and the electron acceptor is about 100 percent. ##STR9##
Furthermore, with the perylene dimer mixture composition components of the present invention there may be permitted larger latitudes and adjustment and design of the physical properties of the photogenerating pigment, such as increasing the photosensitivity, and improving the dispersion stability thereof. Increasing photosensitivity permits, for example, the use of light source at a reduced power rating by, for example, about 40 percent and hence a hardware cost savings. Also, dispersion stability time can be prolonged by more than about 100 percent as the dopants or electron acceptor components added can adsorb and modify the perylene pigment surface resulting in reduced aggregation of the perylene pigment particles.
Examples of electron acceptor materials include polymers and compounds, inclusive of nonpolymers, and more specifically, PMMA-BCFM polymers, carbazoles, fluorenones and fluorenylidene malonitriles. The electron acceptor component can be added to the mixed perylene dimers prior to or during the preparation of photogenerator layer. The relative weight of electron acceptor with respect to the total amount of mixed perylene dimers can vary in embodiments of from about 0.1 to about 20 weight percent, and more specifically, from about 1 to about 16 or 10 weight percent.
Specific examples of electron acceptors are 9-vinylcarbazole, 9-phenylcarbazole, 9-ethylcarbazole, 9-naphthylcarbazole, polyvinylcarbazole, (4-n-butoxycarbonyl-9-fluorenylidene)malonitrile (BCFM), 2,7-dinitro-9-fluorenylidene malonitrile, 2,4,7-trinitro-9-fluorenylidenemalonitrile, 2,4,5,7-tetranitro-9-fluorenylidene malonitrile, 2,4,7-trinitro-9-fluorenone, 4-n-butoxycarbonyl-9-fluorenone, 2-nitro-9-fluorenone, 2,7-dinitro-4-n-butoxycarbonyl-9-fluorenone, 2-t-butyl-4,5,7-trinitro-9-fluorenone, polymers thereof, especially polymers of polymethylmethacrylate (PMMA) and BCFM, and the like.
Imaging members with the photogenerating pigment perylene and electron acceptor mixture of the present invention are sensitive to wavelengths of, for example, from about 400 to about 800 nanometers, that is throughout the visible and near infrared region of the light spectrum. Also, the imaging members of the present invention generally possess broad spectral response to white light from about 400 to about 800 nanometers and stable electrical properties, such as the charging voltage and the photodischarging characteristics remaining relatively constant over long cycling times as illustrated herein.